Problem: Solve for $x$ : $4\sqrt{x} + 1 = 9\sqrt{x} + 6$
Explanation: Subtract $4\sqrt{x}$ from both sides: $(4\sqrt{x} + 1) - 4\sqrt{x} = (9\sqrt{x} + 6) - 4\sqrt{x}$ $1 = 5\sqrt{x} + 6$ Subtract $6$ from both sides: $1 - 6 = (5\sqrt{x} + 6) - 6$ $-5 = 5\sqrt{x}$ Divide both sides by $5$ $\frac{-5}{5} = \frac{5\sqrt{x}}{5}$ Simplify. $-1 = \sqrt{x}$ The principal root of a number cannot be negative. So, there is no solution.